That patent relates to a process for tensioning corona-discharge electrodes which are fixed in bores of frames in dust-collecting electrostatic precipitators. According to the process, each corona-discharge electrode is rod-shaped at one end, an abutment is provided at the rod-shaped end portion, a tensioning wedge is driven between the tubular frame and the abutment and used to tension the corona-discharge electrodes against the frame, and the end of the corona-discharge wire is welded to the tubular frame when the electrode has been tensioned.
To carry out that process, the rod-shaped ends of the corona-discharge electrodes are either formed with an annular peripheral groove or with a pin to provide an abutment. In an alternative mode, a removable abutment is provided at the end of a rod-shaped corona-discharge electrode or the end portion of a strip-shaped corona-discharge electrode is deformed and directly pushed through the bore in the tubular frame and tensioned by a wedge, which is driven through a slot formed in the end portion of the corona-discharge electrode.
It has been found that these modes of carrying out the prior process do not yet meet all requirements and for this reason give rise to a desire for improvement.
In the modes described first, in which an abutment formed by a groove or pin is used, a serious disadvantage resides in that the manufacture of the rod-shaped end portions is highly expensive and for this reason uneconomical. Because this part must be made in very large quantities, even small improvements can result in considerable savings.
The same remark is also applicable to the mode described last, in which the deformation of the end portion of the strip-shaped corona-discharge electrode and the forming of the slot are comparatively expensive.
The technique in which removable abutment is used has not been successful in practice because the collet chuck of the removable abutment often could not withstand the sudden load imposed as the wedge was being driven so that the corona-discharge electrodes often could not be satisfactorily tensioned.